US2237794A

US2237794A - Device for reducing sheet metal

Info

Publication number: US2237794A
Application number: US142217A
Authority: US
Inventors: Sendzimir Tadeusz
Original assignee: American Rolling Mill Co
Current assignee: American Rolling Mill Co
Priority date: 1937-05-12
Filing date: 1937-05-12
Publication date: 1941-04-08
Anticipated expiration: 1958-04-08

Description

April 1941- T. $ENDZIMIR 2,237,794

DEVICE FOR REDUCING SHEET METAL Filed May 12, 1937 9 sheets-sheet 1 INVENTOR. Than/.52 5291021114112 ATTO RN EYJ.

April 3,1941- 'r. SENDZIIMIR 2.237.794

DEVICE FOR REDUCING SHEET METAL Filed May 12; 1937 9 Sheets-Sheet s f I 1" ///ZZ /Z6 /5 I: a Q E615.

- l9 U y {2/ f6 v 17 V 4% 2M T 40:71.52 JE/VDZIMIIE svwqm ATTORNEYS- April 1941- T. SENDZIMIR 237,794

panes You nsnucme SHEET ua'w.

Filed llay 12, 1937 9 Sheets-Sheet 4 INVENTOR.

. J T/@ 15, T401503: d'rlvaz/mg ATTORNEYS.

April 1941- T. sENDzmm 2.237.794

navrcs FOR Rrmusme swam 1mm.

Filed May 12, 1957 9 Sheets-Sheet a lNVENTR. IAasusz SENazIM/E.

ATTORN EYS.

April 8, 1941. 1-. SENDZIMIR 2.237.7 4

navrcn FOR REDUCING SHEET METAL Filed Hay 12, 1937 9 Sheets-Sheet 6 T140505: SENOZIMIR.

1 76. 1 INVENTOR.

ATTORNEYS Awfi fi W41. 2.237.794

T. SENDZIMIR DEVICE FOR REDUCING SHEET llETAL Filed May 12, 1937 9 Sheets-Sheet INVENTOR. 739051152 SENaZIMIE,

ATTORNEYS.

Fla 6.

April 1941- T. SENDZIMIR v 2.237.794

DEVICE FOR REDUCING SHEET METAL Filed May 12, 1937 9 Sheets-Sheet. 3

INVENTOR. 23405032 Sam/02 0112.

ATTORNEY.S

April 8, 1941. I

1'. SENDZIMIR 2.237.794

navxcs FOR nsnucme smm 1mm.

Filed May 12, 1937' 9 Sheets-Sheet a INVE 0R.

Z'qazusz 62w Mme.

BY MQPM ATTORNEYS. 4

Patented Apr. 8, 1941 UNITED STATES PATENT OFF-ICE 2,2 7,194 DEVICE FOR REDUCING SHEET METAL Tadeuu Sendzlmir, Paris, France, assignor to l'he American Bolling Mill Company, Middleto at. Ohio, a corporation of Ohio Application May 12, 1937, tie No. 14 2,2i'l

Y 19 Claims. (ill Bil-iii lily invention relates to means for reducing metal by falling tndtompriswinpertahfit nisrn which is automatic or semi-automatic ih" No. 31,697 filed July 16, 1935; Serial Nofiljmd died July 16, 1935; and Serial No. 83.534 died June 4, 1936. In these applications it have described a certain process oi rolling strip material, wherein the rolling operation, the elongation of a strip may bemaintained constant in spite oi variations of temper and gauge and wherein certain means driven in a predeterned relationship with the mill provide a pre--- determined, but controllable feeding-in speed for the strip, as wellas a predetermined and controllable feeding-out speed, thus permitting, in conjunction with the use of working rolls of very small diameter and rigidly supported ultimately by means of the mill frame, the rolling of strip with great flatness and extreme accuracy in spite oi the variations in the rolling pieces which have been mentioned.

These teachings may be employed in connection with the presentinvention. but are not neeemarily limitations thereon, as will beciearly set torth hereinafter.

In constructing a mill of the character to which the present invention relates, two or more stands of working rolls may be combined in one rrame. Regarding the several stands as constituting a train of working instrumentalities, it willbe seen that as to any particular mill a preceding mill can act as a positivefeeding-in means, while a suceeding mill can act as a positive feeding-out means and the advantages of the former invention secured with less over all apparatus. A difference in the process lies in this that in. the system of my former application the feeding-in and feeding-out devices were es- 'sentially devices having no reducing function,

whereas in the'present case. as respects some of the pairs of working rolls at least, the feeding-in and feeding-out devices have a reducing function,

so that'compensationsin rolling conditions can produce under the influence of varying tensions, a constant rate of elongation, which compensa- 'tions rn iay be occurrinp simultaneously at more than onestandpl woriting rolls.

It must he recogniz edthatihc sction ot a. pair oi reducine rolls, especially of a small-diameter,

is not exactly the same as that or a ieedinp de vice having substantially no reducing function. a is due to the slippase oi the strip within the roll bite which varies both with the tension oi the strip in trout and after the rolls, as well as with the pressure.

at is meant here is that it will act as such ior this purpose, that is for leading the metal at constant predetermined proportion of velocities --se.that the stripwili elongate uniformly and be independent cl ifrehularitieiiin thieleness teni V.

per'and other characteristics of the raw material. However, with a mill as described in this application, the reducingrolls act on the strip in. succession and it will be clear that it a plurality oireducine rolls are considered, their action on the strip resembles very closely the action or a non-reducing feeding device, as they pull the strip -lointly and .ieintly----neutralize any cause (such use. thick spot on thestrip) which may afiect accurate and uniform reduction.

" I have iound that by combining in one frame or stand two or more pairs oi! working rolls of the character described, I obtain very valuable economies-in the weight and size of the mill, since'thesupporting beams or structural framework can be made to support simultaneously two or more working rolls. the'reaction of which at least partiallycounteract each other. The resultant force in the beam. is therefore smaller than it would otherwise be and the structure of the mill does not need to be unduly heavy.

An obvious economy lies in the fact that, n such a device the feeding-in and feeding-,outd vices which do not have a reducing function are required, so that in most instances but one feedlug-in and one feeding-out device need be provided.

Still another important vantage lies in the driving means for a plurality of mills. In a machine of the type described a certain percentage of reduction may be first decided upon for each pair of rolls, and a common rigid geared drive may then be provided for all of them, this drive being suitably connected with the feeding-in and feeding-out devices. Applicant prefers for this purpose, to adopt a percentage of reduction comfortably below the best reduction which could be obtained in each pass, so

simplification and adof the torque transmitted.

It will be readily understood that with a mechanism in which the rigid drive is correctly ad- Justed, the same general rolling principles will apply as those set forth in the co-pending applications above enumerated. Thus tension of a high order per unit of strip section may exist between the feeding-in and the feeding-out machines and the rolls, and also between each adjacent pair of working rolls. Yet such tension Fig. 4 is a sectionalview of a portion thereof taken along the lines 4-4 of Fig. 3. Fig. 5 is a sectional view through the driving means for a mill of the type shown in Fig. 2.

Fig. 6 is an end elevational view with parts in section of the mill of Figs. 2 and 5.

Fig. 7 is an end elevational view with parts in section of the mill of Fig. 1.

Fig. 8 is a top plan view of the mill-of Figs, 2, 5 and 6.

Figs. 9 and 10 are respectively vertical and horizontal sections of a particular type of mill drive which I find advantageous to use.

Figs. 10 and 11 are sectional views. on an larged scale, of a type of indivi aware-331i;-

tion as shown Figrfa:

is merely a result of certain proportions of VeIQcL-HJ FigTIZ is a sectional view taken along line ties imparted to the strip and is not capable in itself of influencing the velocity of any given working part of the mill. However, elongation may be maintained constantly at a predetermined value, the tensions varying as may be required to accomplish the predetermined elongation. Of course, a condition of correct adjustment would be upset with any such mechanism if any one of the elements should be disturbed. For example, if a pair of working rolls were substituted in any given mill for a pair of larger diameter, the condition of adjustment would not be the same. Inmy mail-adjustment within certain limits can be ,corrected by the adjustment of the roll pass of one or more pairs of rolls.

I have solved the main difiiculty connected with the operation of a system of this sort. This dimcu ty is to ascertain, during the actual working of the mechanism, which if any of the pairs of rolls needs special adjustment and if it does, how much adjustment is needed. My solution is based upon actually accomplished the reduction it was intended to accomplish, it is bound to require a certain torque to do it. If the ratio of reduction is upset, however, slightly, the tensions both in front of and behind the rolls are altered and so also is the actual work of reduction accomplished by the rolls. All three of these factors tend to change always in the same direction; that is to say they do not counteract each other. Therefore it is possible to provide for each a simple means to give a constant measurement The operator, in the operation of the mechanism, therefore, has only to see that the measured torques do not vary too far from predetermined values, by suitably ad- 55 lusting the roll clearance or screw-down so called, on one or more of the pairs of rolls in accordance with the torque measurements. All of this can be done during the continued operation of the mechanism.

Various objects of been setforthhereinabove, or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain construction andarrangement 'of parts of which I shall now describe certain exemplary embodiments. For clarity reference is now made to the drawings wherein:

Figure 1 represents a sectional view through a millembodying my invention. V

Fig; 2 is another sectional view through a mill of slightly different character.

Fig. 3 is. a sectional view on an enlarged scale of a type of individual mill construction as shown on Fig. 1.

6 my invention which have mechanism, however, such 30 the fact that when a pair of rolls pair of working rolls ,0 rows of backing rings i2i2 of Fig. 11.

By reference to Figs. 1 and 2 it will be noted that my mill comprises in general a housmgwfliich at 6, then between the

parts

3 and 2 over a sheave marked 7, back between the parts 2 and i and over a feeding-out device indicated generally at 8. I have shown mills indicated at A, A, B, B, etc. In-Fig. 1 four such mills are shown, two operating on the strip 5 during its downward passage and two operating on the strip 5 during its upward passage. In Fig. 2 I have shown nine mills compressed in the same stan Now it will be noted,-that-,the member 2 is common to the several mills and supports oppositely directed pressure strains, whereby this part does not need to be so heavy. Moreover it will be noted that the mills are oia type in which the forces applied to the outer mill frame members I and 3 are not wholly normal to the axis of the frame members and therefore in part counteract each other. The mill frame or housing comprises the parts i, 2 and 3 and is either made of one piece of metal, or of several parts which are solidly and rigidly fastened together in any way desired.

As to the mills themselves, I prefer to use such constructions as are shown in greater detail in Figs. 3 and 4 and 11 and 12. Modifications in these structures may be made without departing from the spirit of my invention. The various structures in general are, described and claimed in my co-pending applications referred to above. They differ from each other in various ways, such as in the number of elements which back up the 0 Figs. 3 and 4 and 11 and 12, it being understood that those particular structures do not constitute a limitation upon my invention as hereinafter claimed.

I have shown in these figures a mill, having a housing portion 3. .A pair of working rolls 9 and in are indicated as operating upon the strip 8. In the particular mill shown on Figs. 3 and 4, the roll I0 is backed up by a pair of intermediate rolls ii and I! which in turn contact three parallel l9, molmted on shafts l1, l5, l1, and interspaced with disc-like bearing members'l8 resting directly in circular channels provided in the beam 3 of the mill stand. Clamps I are bolted to said bearing members ll jointly forming a bore for the necks of shafts i7 and Ii.

. The mill housings are so constructed 'thel 'The common shaft is shownin Figs.

face it carries teeth which pending case may be employed here. When rolling hot-rolled-stock of heavier gauges, such as /2 or I prefer to use such feeding-in devices as do not bend the stock, one or more pairs of pinch rolls, for example. Or I may dispense with the use of the feed-in device entirely, as with such heavy stock the several first pairs of reducing rolls taken in conjunction, play the role of a feeding-in device for the finishing group of rolls.' Ordinarily the strips are welded together, always the last end of the preceding to the first end of the following coil, as at 6a to avoid threading the mill each time a coil is finished and secure less interruption in operation.

The feeding-out machine has been indicated generally at 8 and this again may be as shown or it may comprise any of those devices which have been set forth in my co-pending applications hereinabove referred to. The strip may proceed I to a shear 28 and may be coiled up alternately into different coils as at 29 and 30.-

Considering the assembly of mills and feeding devices thus far set forth, it will be noted that the first mill in the train is positively fed by the feeding-in device 6 and that each successive mill in the train is fed by the fore-going mill. as at 3| and 32 as to guide the first end of the strip from one mill to another. It is preferable that from the point of its entry into the first pair of rolls until it emerges from the finishing rolls, the strip will be covered with a bath of oil. The construction of my mill is such that the entire interior of the mill housing may be submerged in oil which not only lubricates and cools all of the bearings and all bearing surfaces, but also lubricates and cools the strip and washes away any foreign material on its surface. To facilitate this, the return sheave I is preferably contained in an oiltight housing or sump 33. Oil may be delivered to the entrance and housing by means indicated at .34 and 35 and will flow down between the housing members I, 2 and 3 to the sump 33, whence it may be withdrawn through a pipe 36. The oil is, of course, circulated rapidly and may be cooled and filtered outside of the mill after withdrawal from the by friction, so as to ly connected by shafts48 and 48 with the working rolls of a mill. By this arrangement side forces are neutralized and only torques are transmitted and I am able to transmi large forces by a gearing which occupies very little space, being particularly limited in this respect as the

shafts

44, 49 have practically the same diameter as the reducing rolls themselves, and the introduction of this type of a gear box greatly improves this mill. With the type of mill as shown on Figs. 1, 3 and 4, I prefer to drive the intermediate rolls II and [2 which in turn, drive the working rolls ll be able to use working rolls of such a small diameter as would not stand the necessary torque. In Fig. 7 I have shown the shafts 48 and 49 connected directly to the intermediate rolls II and I2. The length of the shafts 48 and 43 will be such as to permit Slight displacement of the rolls II and i2 and eliminate the necessity for universal joint drives, although such drives may be employed if desired. It will be understood, of course, that where desired, the rolls II and I! for replacement purposes may be provided with separable couplings for attachment to the shafts 48 and 49. In Fig. 7 it will be seen that I have made my mill oil-tight for purposes hereinabove described by side plate means 50 and 5| and that suitable glands 52 are provided where the shafts 48 and 49 pass through the plate 5i.

In the drives for the mill each of the individual drives connected with the shaft 33 are calculated for the particular speed ratio required for'the individual mill taking into account the diameter exit portions of the mill pipe 33 and before re-delivery to the spouts 34 and 35. It is preferable to provide means for pumping the oil in and out very quickly so as to avoid loss of time in case an adjustment or repair to the mill or a change of rolls is necessary.

Allof the workingrolls excepting preferably a t st stand, are driven by fixed gearing from one common source of power. This is illustrated best in Figs. 5 and 6 where the main mill motor is indicated at 31 and. drives a common shaft 33. is connected by worms 39 to driving means 40 for the several rolls on the train. The particular power transmitting drive 9 and 10 where the shaft 33 is shown as slidably keyed to the worm 39. This worm meshes with the member 40 which is journaled by suitable bearing means 4| in a housing 4!. The member 40 is teethed on its outer surface to mesh with the worm 33. On its inner surmesh with three

pin ions

43, 44 and 45. The p rpose of this particular type of gearing is to minimize the conversion of torque to displacement forces on the drive gears. It will be seen that each of the

gears

43, 44 and are drivenfrom both sides. As a consequence they do not need heavy bearings in end members 43 and 41 of the housing 42. An adjacent pair of gears, e. g. 43 and 44 may be directwithin very narrow limits of the working rolls and the speed of the strip (as determined by previous elongation as well as the entering speed) of such pair of rolls. Since each of the mills in the stand can effect a reduction upon the strip, it will be obvious that each successive mill be geared tooperate at a higher speed than the preceding mill.

The diameter of the rolls must also be taken into consideration since the most economical way oi using the rolls would seem to be to start with a new pair of working rolls on the first or roughing mill and then as they wear transfer them to successive mills in the train, the finishing mill having rolls always of the smallest diameter, so as to be able to use the reducing rolls to the very end of their useful life, and yet have the range of roll diameter, for each individual reducing mill, which makes the use of this rigidly geared drive possible.

Referring again to Fig. 9 the worms 33 may be slidably keyed to the shaft 38. Each worm is supported in radial and thrust bearings 53 and 54 in the housing member 55. One of the thrust bearings at least is provided with a thrust measuring ring 56, or pressure indicating ring which Thus may be of any of several known types. it may be a compressor body filled with a liquid or a body containing a piezo-electric crystal or a magnetic stress measuring device or the like.

justment of the roll pass while it is running in a way which has been indicated above. Thus in will be clear, such an adjustment can be accomplished by automatically acting devices set in mo tlon by the pressure indicating means.

The main motor 31 is also connected with the ifeeding-in and feeding-out

devices

6 and 8 respeetively as will be described, and finally may be caused to drive the final pair of working rolls in the stand. Any direct mechanical action be tween the motor 31 and such devices may be employed. For convenience in the mill illustrated, a piston-hydraulic drive has been adopted which, excepting for a very insignificant amount oi leakage of oil past the pistons, is the substantial operating equivalent of a train of gears. In addition to its fixed ratio of drive, however, it

can easily be made to have an adjustable stroke and when so made, has the further advantage at being variable by infinitely small stages it necessary. Such a transmission always comprises two parts, the one being a pump, the other a motor. The pump furnishes oil under pressure to the motor so that the motor is bound to turn euactly in proportion with the quantity of oil supplied. Hydraulic transmisson mechanism of this general type is available on the open market and, therefore, is not herein described in detail.

By reference to Fig. 8 it will be seen that the motor 31- drives by means of chains 51, a variable stroke hydraulic pump 58 which furnishes oil to two motors, 59 and 69, each having variable strokes. The particular connections 58a, 59a and too between this pump and the several motors have not been carried through on the drawings but will be readily understood by the skilled worker in the art. The first of these motors is a motor 59. This motor is connected with the ileeding-out device 8 by means of a pair of gears ti; but is also connected with the feeding-in device 6 through a chain drive 6| the sprockets ilor which, 62 and 83, are proportioned in size in a way appropriate to the particular elongations desired. The chain sprocket 63 is cut'or formed. on the outside of a ring gear. The planetary or satellite gear is indicated at 64, the spider of which 6311 is connected directly to one or the shafts of the feeding-in device 6. The sun wheel or center wheel 64a of the planetary transmisslon is connected through a shaft 65 and gears at to another hydraulic device indicated at 61. in this device there is combined both a hydraulic motor I! (which drives the shaft 55 through the pair of gears 66) and a hydraulic pump I i. The

pump H is driven through a chain drive 88 or other suitable transmission from the motor 59.

It will be clear that with this arrangement, when the pump ll is set at zero stroke, the sun wheel 01 the satellite gearing 64 will not turn Iand thereiore the transmission GI between the feeding-in and feeding-out devices will be entirely rigid as it it were a trainoi gears.

when an adjustment oi this fixed ratio is necessary, the stroke of the pump portion oi the hydraulic transmission 61 will be so adjusted as to iurnlsh enough oil to the motor portion of the transmission to make the sun pinion or the planetary gearing 64' turn at a desired speed so as to add to or subtract from the original ratio. However, when such adjustment has been made the new ratio will likewise be positive and unyielding as if it were a train of gears. This system of positive and adjustable transmisison has been discussed in detail in the co-pending applications for Letters Patent, hereina'bove referred to.

The second motor is the motor 69. As shown most clearly in Fig. 5 this motor is coupled by means 10 to the last pair of working rolls in the mill combination. For simplicity in this application 1 have considered the motor 89 as being driven by oil from the-pump i8, 'although'in practice it may be simpler to use a separate pump for it. The motor is of exactly the same piston type as has hereinbefore been discussed and has an adjustable stroke. With the same quantity oi oil per minute the smaller the stroke the more rapid the motor will turn. The whole drive arrangement which I have shown and described permits one to start with a strip of raw material or the desired gauge, within the limits actually met in practice and to carry it down to substan-- tially any gauge desired, always maintaining the proper velocities and consequently the proper tensions between the feeding-in device and the first pair or working rolls, .then between each pair of rolls and the next one and finally between the finishing pair 01 rolls and the feedingout device.

The purpose or providing separate drives for the final mill is to permit changes of gauge without over all readjustment. This may be accomplished in my system by eliminating the operatring effect or one or more oi! the latter mills in the train. This can be done by opening up the mills or can be done by removing the working rolls. The final pass is given by the final mill with the separate drive giving a very high degree or flexibility of operation.

While I have described in some detail a certain type 01 driving means, it will be understood that others can be employed if desired. It is evident that the mill can be made to work with an entirely rigid gear connection for example irom the feeding-in device through all the working rolls down to and including the feeding-out device; but the ratio between the feedin -in and feeding-out devices of the mills being thus set at a fixed ratio which cannot be varied, only one definite reduction can be obtained. Thus with a givenmaterial it would be possible under these circumstances to roll to but one finished gauge. sired, a thinner starting piece would have to be employed. On the contrary in the arrangement which I have particularly described or an arrangement including some transmission means of equivalent flexibility, I can produce almost any specific reduction desired. This can be accomplished by adjusting the final pass on the finishing. rolls and by the omission of the operation of one or more preceding mil-ls as I have indicated. Naturally this adjustment applies only to the making or lesser reductions than the maximum. A certain possible maximum reduction for the mill cannot of course, be exceeded; but the mill may be so constructed as to be capable of a maximum reduction in excess of commercial requirements.

0n the other hand, the individual pairs oi rolls or my mill may be driven by other flexible Where a lighter finished gauge was demeans. without departing from my mill frame invention.

They may, for instance, be driven, each pair of rolls, or even each roll (from opposite sides of the mill), by a piston-type ydraulic motor, while the feeding device or devices are similarly driven. In such case, an absolute rigidity of maintaining the speed relationship of all these instrumentalities can still be preserved, while the reduction by each individual pair of rolls can be adjusted at will. same as the tension in front and after the rolls; and so the sive to buy. shall be capable of being utilized better and give a higher reduction than with the gear drive as first described.

Or else individual or group electric motors may be used, employing such speed control means as are available. In this case all the advantages of the frame construction and roll support are there, but the predetermined speed relationship cannot be obtained with the same accuracy and without a lag, and through accelerations and stops, as in the case of the drives hereinabove described. Such electric drive may, however, give tolerably good results for many purposes.

As far as the housing or frame of the mill is concerned it is essentially a one piece housing: but it can also be made of several pieces fastened together by bolts or other means of sufilcientstrength so that under conditions of full load on all rolls, there is still a considerable pressure on all parts of the surfaces of Junction. The frame is characterized by the fact that the roll supporting beams are not loosely connected with the rest of the frame with it. that is to say, the resistance of the bending forces which such beams ofier is still further increased by their rlgid connection with other parts of the frame. This principle has also been described in the applications referred to. The frame, as shown in Fig. 2 shows a staggered arrangement of the working roll assemblies. In

mill, although more expen-- but from one solid body of all it permits the saving of material in the frame. Secondly. it makes it very easy to work in a complete bath of oil as has been described. Thirdly, the bottom pulley gives the strip an opportunity to cool down sufficiently especially near the surface after the roughing treatment and before entering the finishing group of rolls.

Finally there is the important advantage of dividing the mill and its operations into two floors. The mechanics, roll grinders, and adjustment menparry on their operations on the lower floor as illustrated, while the handling of without department from the spirit of it.

the strip'both in raw and finished condition is carried on on an upper floor. Thus the several operations do not interfere with each other.-

Although not shown in the drawings, it is. of course, preferable to provide for the welding of the raw strip into one continuous length before it enters plished with any suitable mechanism. However, my mill is not restricted to the rolling of a continuous supply of material and strip stock of finite length may be sent through it if desired. I have already explained how the mills in the frame are caused to be self-threading. For this purpose also I provide in connection with the return sheave I suitable guide means II for leading the strip from one mill section to the other. 4

- Modifications may be made in my invention Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: l. A method of reducing strip metal which consists in passing it successively through two or more pairs of reducing rolls while driving said reducing rolls at a fixed ratio of speed to each other. controlling the rate of feed of the strip metal to the first pair of reducing rolls by a non-reducing, positive feeding instrumentality and controlling the rate of withdrawal of the metal from the last pair of reducing rolls by a Fig. 1 there is an opposite arrangement. On non-reducing. positive instrumentality, so that both figurm it will be apparent, however, that the feeding-in and feeding-out of the metal to much metal and space is saved on all beams 5 the several pairs of reducing rolls bears a fixed which support rolls lying on the inside of the mill ratio of speed to the speed of the reducing rolls. frame. Not only is one beam in this position 2; That method of reducing strip metal which enough insteadof two, but also such an interconsists in passing a strip successively through mediate beam can be made .thinner and lighter than would be possible with an outside beam because the greater part of the forces counterbalance each other. The savings in weight. on the outside beams supporting two adjacent rows of backing rings, like the beam H in Fig. 2 is not so pronounced as with the inside beams like 6. but still it is quite considerable.

The mill illustrated in Fig. 1 is shown as having only four pairs of working rolls but is indicated as having also the intermediate supporting rolls which have hereinabove been described in detail. The provision '02 these rolls avoids even theslightest marking that the in-. dividual supporting rings might produce on. the working rolls as they bore directly against the working rolls. Excepting for this consideration and considerations of space, the number of worka feeding-in apparatus having substantially no 5 reducinglfunction, then through at least two feeding-out appara reducing function ing rolls in any given mill combination will usually be determined by considerations of the great-= est reduction that the mill may be called upon to produce. "I'hearrangement of the rolls in such a way that the strip first passes down- .wardly through a series of mills then runs around a shows and goes upwardly again through a series of mills is not essential but it pairs of'reducing rolls, and finally through a feedingwut apparatus having substantially no reducing function and causing the speeds of all of the mentioned instrumentalities to bear a certain pggieterihined constant relationship to each 0 i;

3. That-method of reducing strip metal which consists in passing a strip successively through a feeding-in apparatus having substantially no reducing function, then through at least two pairs of reducing rolls, and finally througlp a and causing the speeds oi all 4. In a rolling mill assembly a housing, a plurality of interspaced rolling means in said housoffers some important advantages in itself. First a non-reducing, positive feeding-1n apple ratus and a non-reducing, positive feeding-out apparatus, and positively acting mechanical mothe mill. This may be accom-' 4 having substantially no housing, said housing comprising a plurality or beams for supporting said working rolls throughout their length, one at least of which beams is located to act as a supporting means common I to interspaced pairs of working rolls.

"l. A continuous rolling mill comprising a housing, a plurality of pairs, of reducing rolls located in said housing, saidhousing having portions acting as a common support for interspaced pairs of said reducing rolls substantially throughout their working length, said reducing roll pairs so arranged in said housing that'a strip of mavariations in load, and .means for separately driving the last pair or working rolls. a

13. In a rolling mill a housing comprising beams parallel to the working rolls, a plurality of interspaced working rolls mounted in said housing and supported in their length by said beams for housing and supported in their length by said rolling a strip passing therethrough, said beams being shaped intermediate said pairs of working rolls to lead a strip of material being operated upon from one pair of working rolls to the next.

l4. In a rolling mill a housing comprising beams, a plurality of working rolls located in said beams in interspaced parallel series whereby a strip or material to be operated upon can be caused to pass twice through said housing in opposite vertical directions in said interspaced series of working rolls, said beams being shaped terial being acted upon first passes through said housing in one direction between at least one pair of reducing rolls and then passes in the opposite direction through said housing between one other pair of reducing rolls.

p. A continuous rolling mill comprising a housing, a plurality of pairs or reducing rolls located in said housing, said housing having portions actling as a common support for interspaced pairs or said reducing rolls substantially throughout their working length,.said reducing roll pairs so arranged in said housing that a strip of material being acted upon fir t passes through said housing in one direction between at least one pair of reducing rolls and then passes in the opposite direction through said housing between one other pair of reducing rolls, said mill also comprising a feeding-in device, a feeding-out device and a sheave over which said material runs intermediate its passages through the housing.

d. A common drive for several pairs of reducing rolls situated in one housing and comprising a single drive shaft with a plurality o1 pinions keyed thereto, a plurality of -gears meshing with cold pinions, each gear being connected to a pair oi working rolls in said housing, and a device l'or continuously indicating the torque transmitted by it fitted to each of said pinions.

id. In a continuous rolling mill a plurality 0! rs of reducing rolls, a common drive for said pairs of reducing rolls, said drive operating to intermediate said working rolls to lead said strip of metal from one pair of working rolls to the other, a sheave mounted to conduct said strip from one series of working rolls to the next, and guide meansior conducting said strip about said sheave. v

15. A method of reducing stripmetal, which consists in passin it successively through two or more pairs of reducing rolls in tandem, said pairs of rolls being backed up throughout their length .on stationary supporting means, the said stationary means serving fixedly to interspace said pairs of rolls and maintaining the contour of the said reducing rolls in spite of substantial variations or rolling pressures, and, driving said reducing rolls at a fixed ratio oispeed to each other during the rolling operation.

' 16. A method or reducing strip metal, which consists in passing it successively through two or more pairs of reducing rolls in tandem, said pairs of rolls being backed up throughout their length on stationary supporting means, the said stationary means serving fixedly to interspace said pairs of rolls and maintaining the contour of the said reducing rolls in spite oi! substantial variations or rolling pressures, driving said reducing rolls at a fixed ratio of speed to each other during the rolling operation, controlling the rate of feed 01' the strip metal to the first pair of reducing rolls by a non-reducing. positive Ieeding maintain a ii-xed ratio of speeds between said several pairs of reducing rolls, and means for measuring the torque transmitted by said common We to each of said several pairs of reducing rolls, whereby in accordance with such measureents, adjustment or the roll passes may be made. Y

. ii. In a continuous mill 0. non-reducing, p nitlve feeding-in device, a plurality of pairs oi working rolls, and a non-reducin p itive feeding-out device and means for transmitting torque to said several instrumentalities continuously at predetermined speed ratios.

it. In a continuous mill 0. non-reducing. posi tive feeding-in device, a plurality 01 h pairs of working rolls and a non-reducing. positive feedeach of said instrumentalities excepting the last instrumentality, and controlling the rate oi withdrawal of the metal from the last pair of reduoing rolls by a non-reducing, positive feeding instrumentality, while driving said feeding in strumentalities at a fixed ratio of speed to the speed of the several rolls.

17. In a singlehousing rolling mill, containing a plurality 0! pairs oi working rolls, arranged to operate as a tandem mill, a housing, comprising beams supporting said working rolls substantially throughout the working length thereor, and members connecting said beams, at least one 01 said beams being located so as to act as a support to more than one working roll, said workhr' rolls so supported being located in such manna. that the pressur es applied thereby to said mill at predetermined speed ratios inspite of 7 of strip material is between said supportin members through a pluralityot pairs of working rolls.

' 19. In a single housing rolling mill, containing a plurality 01' pairs of working rolls, end frame members, parallel supporting members located between said end frame members, and acting as supporting means throughout the length of at least one roll of a plurality of pairs, so that said supporting members are each common to a plurality of pairs of rolls, and so that the passage of strip material is between said supporting'members through a plurality of pairs oi! working rolls there being at least three of said parallel supporting members so that the passage or said strip material is at least twice through said mill between said end frame members in opposite di rection. I

TADEUSZ SENDZIMIR.